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To rip DVD movie to ogg format using ffmpeg, follow these steps.
1) find the vob files on the mounted video DVD in VIDEO_TS that stores the movie itself. There would be a few other VOB files that stores splash screen or special features, the vob files for the movie itself can be identified by its superior size. You can verify these vob files by playing them directly with a player (e.g. mplayer)
2) concatenate all such vob files, pipe to ffmpeg
3) calculate the video size and crop size. The ogg video size must be multiple of 16 on both width and height, this is inherit limitation of theora codec. In my case I took 512x384.
The -vcodec parameter is necessary because ffmpeg doesn't support theora by itself. -acodec is necessary otherwise ffmpeg uses flac by default.
I'm not well enough versed in the differences between ffmpeg & mencoder to know which one is better.
i have a large video file, 500+ MB, so i cant upload it to flickr, so to reduce the size i split it into 2 files. the command shows the splitting for the first file, from 0-4 minutes. ss is start time and t is duration (how long you want the output file to be).
credit goes to philc: http://ubuntuforums.org/showthread.php?t=480343
NOTE: when i made the second half of the video, i got a *lot* of lines like this:
frame= 0 fps= 0 q=0.0 size= 0kB time=10000000000.00 bitrate= 0.0kbit
just be patient, it is working =)
-i = input file name
-s = set frame size, qcif=176x144
-vcodec = force video codec
-r = frame-rate [default = 25]
-b = bit-rate [200 kb/s]
-acodec = force audio codec
-ab = audio bitrate in bits/s [64k]
-ac = no. of audio channels 
-ar = audio sampling frequency [44100 Hz]
-sameq = use same video quality as source (implies VBR)
-f = force format
-y = overwrite output files
Yet another x11grab using ffmpeg. I also added mic input to the capturing video stream using alsa. Yet I need to find out how to capture audio which is currently playing.
This command takes a set of images (from a render, for example), and converts them into a format conforming to the Blu-ray spec, or at least the version on the Wikipedia page.
Convert those .mov files that your digital camera makes to .avi
Adjust the bitrate (-b) to get the appropriate file size. A larger bitrate produces a larger (higher quality) .avi file and smaller bitrate produces a smaller (lower quality) .avi file.
Requires ffmpeg (see man page for details)
(tested with canon camera MOV files)
ffmpeg -i input.mov -sameq -vcodec msmpeg4v2 -acodec pcm_u8 output.avi
ffmpeg -i input.mov -b 1024k -vcodec msmpeg4v2 -acodec pcm_u8 output.avi
Record audio to an MP3 file via ALSA. Adjust -i argument according to arecord -l output.
Record from a webcam, audio using ALSA encoded as MP3, video as MPEG-4.
There are some pretty good live performances on late night TV. With Mythtv I record David Letterman, Jimmy Fallon, and Conan nightly all in HD from over the air broadcasts. If I find a live performance I like I copy it to my Rockboxed iPod using this command. The Rockbox firmware knows how to downmix 5.1 audio. The command above extracts the audio from the video starting at 58 minutes and 15 seconds. It ends at the end of the file since this was the last performance of the recording. The command creates an ac3 file. I copy the ac3 file to my Rockbox iPod and rock on.
This converts any media ffmpeg handles to flash. It would actually convert anything to anything, it's based on the file extension. It doesn't do ANY quality control, sizing, etc, it just does what it thinks is best. I needed an flv for testing, and this spits one out easily.
Converts all ogg files to mp3 files in the current directory.
First, we convert the VMware avi (VMnc format) to the Microsoft avi format. Next, we convert the Microsoft avi format to FLV format.
You can play around with the -r switch (rate per second) and the -b switch (bitrate). But, if those get larger, so does your FLV file.
The option -an disables audio recording, -f forces the use of video4linux for the input, -s sets the video to the size 320x240, -b sets the recording bitrate, -r sets the frame rate to 15fps, -i gives the input device, -vcodec sets the output format.
Press Q to stop recording or you can specify the recording time with the -t option like -t 00:1:30
Grab X11 input and create an MPEG at 25 fps with the resolution 800x600
rips the audio and video stream of a movie. The two streams are stored separately.
This assumes that there is a 10.2 sec delay between the video and the audio (delayed).
To extract the original video into a audio and video composites look at the command on extracting audio and video from a movie
Takes an mpeg video and coverts it to a youtube compatible flv file.
The -r 25 sets the frame rate for PAL, for NTSC use 29.97
-vn removes tha video content, the copy option tells ffmpeg to use the same codec for generating the output
I used an flv in my example, but it'll work on any file ffmpeg supports. It says it wants an output file, but it tells what you want to know without one.
This converts all m4a files in a dir to flv. You can just swap the m4a bit to anything else ffmpeg supports though, and it'll work.
This is handy for making screenshots of all your videos for referring to in your flv player.